Effects Of Taurine On ECG And Serum Troponin In Myocardial Ischemic Rats

AIM To observe the effects of pituitrin administrated intravenously on electrocardiogram(ECG), and the effects of taurine, diltiazem and their combination on the ECG changes induced by pituitrin in conscious unrestrained rats, and on experimental myocardial infarction in anaesthetized rats. METHODS ECG (leadII) was recorded and analyzed with Data Science International (DSI, USA). Cardiac infarction model was made by ligation of left anterior desending coronary artery and serum cardiac troponin I ( cTnI), creatine kinase MB(CK-MB) activities and the infarcted size were measured. RESULRS 1.The ECG changed regularly anddose-dependently after injection of pituitrin 0.25-4.0 U-kg-1 through tail vein, especially after 15s. 2. Half an hour before pituitrin intravenous injection, Tau ( 100mg-kg-1, 200 mg-kg-1 400 mg-kg-1 ) injected intraperitoneally (ip) inhibited the T wave elevation and heart rate decrease induced by pituitrin intravenous injection; compared with NS + pituitrin group, T wave elevation were decreased from 1.77 0.165 to 1.60 0.128(P<0.05) , 0.93 0.058(P<0.01) , 0.58 0.073 (P <0.01) andheart rate were increased from 170 30.9 to 249.9 30.9, (P <0.01 ) 375.0 31.2 (P <0.01 ) , 380.1 48.9 ( P <0.01 ) respectively; In the combination group (DTZ 16mg-kg-1 + Tau 200 mg-kg-1), T wave elevation was decreased from 1.71 0.184 to 0.62 0.066 (P <0.01) , but no significant effects were observed on heart rate. 3. Tau ( 100 mg-kg-1, 200 mg-kg-1, 400 mg-kg-1) injected intraperitioneally (ip) decreased the serum cTnI, CK-MB and diminished the infarcted size; Compared with model group, the serum cTnI were decreased from 26.33 4.93 to 10.50 1.87 (P <0.01) , 5.00 1.41 (P <0.01) , 2.83 0.75 (P <0.01) respectively; The serum CK-MB were decreased from 182.33 24.46 to 131.16 24.39 (P <0.01) , 121.17 20.84 (P <0.01) ,95.67 7.31 (P<0.01) respectively. In the combination group (DTZ 16mg-kg-1 + Tau 200 mg-kg-1), the serum cTnI and CK-MB were decreased to 2.25 0.92 (P<0.01) , 95.67 7.31 (P <0.01 ) respectively. These three indices in the combination group were significantly lower than those in single drug treated groups. CONCLUSION 1.T wave elevation of ECG (Lead II) can be induced dose-dependently by pituitrin injection through tail vein. 2.Taurine ip dose-dependently inhibited the T wave elevation and the heart rate decrease induced by iv pituitrin in conscious unrestrained rats. 3.Taurine decreased serum cTnl and CK-MB, and diminished the infarcted size in myocardial infracted rats. 4.The results suggest that there is a synergism between taurine and diltiazem in anti-ischemia.